A diamond is an allotrope of carbon wherein a carbon atom is connected to four other carbon atoms in a tetrahedral position. (Or something like that.) How did I know this? I didn't! I just guessed. All I knew was that diamond is pure carbon. I don't even know what the hell an allotrope is.
But why are diamonds students' best friends?
1} When the teacher asks something about it, you don't even have to listen to the question! This will allow you have undisturbed daydreams (that is, if your teacher's crazy enough to dedicate a whole session to discuss the properties of diamonds.. which is unlikely). If you hear "allotrope," "carbon," and "tetrahedral" in one sentence, you already know the answer. (Clue: It's not buckminsterfullerine.*)
2} You can use it to bribe your teachers. Or you can just pelt them with semi-large chunks of it 'til they give you a high mark. Diamonds are hard to get, but they're totally worth the effort.
3} The chemical composition's ridiculously easy to write.
|It's just a big, fat C.|
* A shorter name for that would be fullerite. The keywords for that are "allotrope," "carbon," "60 atoms," and "soccer-ball-like."
Lesson for the day: 9gag can be educational. No, I'm not crazy... yet.